One of the most basic needs of investigators studying skin disease is the ability to use tissue sections to analyze the pathological changes at the tissue and cellular level. This analysis requires access to specialized equipment for tissue processing and to highly trained personnel, neither of which can be afforded by most research laboratories. Furthermore, since qualitative and quantitative evaluation of skin and skin appendages requires precise and reproducible orientation of skin sections, histology services not specialized in skin generally produce skin sections of substandard quality. Therefore, the objective of the Morphology and Phenotyping Core is to provide investigators with the tools and expertise to process and analyze skin samples. The Core owns the equipment necessary to process and section skin samples and employs a histology technician trained in processing skin samples. Thus, the Core is able to provide investigators with high quality processing and sectioning of skin samples as well as with the preparation of basic histological stains. Whereas histological analysis of skin samples represents the first step in analyzing skin phenotypes, subsequent analyses include immunostaining for various markers of skin proliferation and differentiation. The Core possesses a wide variety of custom-made antibodies that recognize such markers and will provide investigators with immunostaining services using these antibodies. The Core will also offer in situ hybridization services to allow investigators to determine transcript expression patterns of their gene of interest. Finally, the Core will offer consultation services including assistance with harvesting skin samples, analyzing histological stains, analyzing antibody staining results, and analyzing in situ hybridization results.